Device, system and method for cross-talk reduction in visual sensor systems

ABSTRACT

A device, system and method of cross-talk reduction in visual sensor systems is provided. A display device is configured to provide first images viewable by a first visual sensor system, and second images, viewable by a second visual sensor system. The first images and the second images have common features which align when the first images and the second images are provided concurrently. The first images comprise wavelengths viewable by the second visual sensor system. A controller determines a second visual sensor system intensity component of the first images using a response curve of the second visual sensor system. The controller reduces intensity of the second images provided at the display device by the second visual sensor system intensity component of the first images, at least when the first images and the second images are concurrently provided.

FIELD

The specification relates generally to projectors and display devices,and specifically to a device, system and method of cross-talk reductionin visual sensor systems.

BACKGROUND

When displaying an image, it may be desired that both unaided human eyes(human visual sensor system or HVS system) and viewers looking throughnight vision (NVIS) goggles may be able to see the appropriateinformation. Unfortunately, the HVS system and NVIS goggles haveoverlapping sensitivity regions such that red components of HVS systemviewable images will stimulate NVIS goggles. Thus, items in the scenecontaining red will appear in the NVIS goggles. If an RGB display systemis used, it is likely that most items will contain some red as theprimaries are mixed to create all colors, and unless the desired greenand blue gamut primaries match the display system's native primaries,even those colors will include some amount of red and thus appear in theNVIS goggles. The desired image for the HVS system and NVIS goggleslikely differ, so separate image generators are often used, and the NVISimage generator may not be aware of the color or brightness of the HVS(visible) image at any point in the NVIS image.

SUMMARY

In general, this disclosure is directed to a device and method forcross-talk reduction in visual sensor systems in which first imagesviewable by a first visual sensor system and second images viewable by asecond visual sensor system are concurrently provided at a displaydevice. A second visual sensor system intensity component of the firstimages is determined using a response curve of the second visual sensorsystem, and the intensity of the second images is reduced by the secondvisual sensor system intensity component of the first images. Inspecific implementations, one or more projectors project RGB(red-green-blue) images viewable by a human visual system, and infraredimages viewable by a night vision (NVIS) sensor system (which caninclude, for example NVIS goggles). An NVIS component of the RGB imagesis determined using a response curve of the NVIS sensor system, forexample as a function of wavelength, and the intensity of the infraredimages is reduced by the NVIS component of the RGB images. However,systems and methods provided herein can be applied to other systems anddevices where images are provided concurrently to different visualsensor systems where cross-talk occurs there between.

In this specification, elements may be described as “configured to”perform one or more functions or “configured for” such functions. Ingeneral, an element that is configured to perform or configured forperforming a function is enabled to perform the function, or is suitablefor performing the function, or is adapted to perform the function, oris operable to perform the function, or is otherwise capable ofperforming the function.

It is understood that for the purpose of this specification, language of“at least one of X, Y, and Z” and “one or more of X, Y and Z” can beconstrued as X only, Y only, Z only, or any combination of two or moreitems X, Y, and Z (e.g., XYZ, XY, YZ, XZ, and the like). Similar logiccan be applied for two or more items in any occurrence of “at least one. . . ” and “one or more . . . ” language.

An aspect of the specification provides a system comprising: a displaydevice configured to provide first images, viewable by a first visualsensor system, and second images, viewable by a second visual sensorsystem, the first images and the second images having common featureswhich align when the first images and the second images are providedconcurrently, first images comprising wavelengths viewable by the secondvisual sensor system; and, a controller configured to: determine asecond visual sensor system intensity component of the first imagesusing a response curve of the second visual sensor system; and, reduceintensity of the second images provided at the display device by thesecond visual sensor system intensity component of the first images, atleast when the first images and the second images are concurrentlyprovided.

The system can further comprise a memory storing: a response curve ofthe second visual sensor system and spectral radiance curves of one ormore of: light sources of the first projector; and the first images.

The display device can comprise one or more projectors configured toprovide the first images and the second images concurrently by one ormore of: interlacing the first images and the second images; alternatingthe first images and the second images; and co-projecting the firstimages and the second images.

The first visual sensor system can comprise a human visual system andthe second visual sensor system can comprise a night vision sensor(“NVIS”) system.

The first visual sensor system can comprise a human visual system andthe second visual sensor system can comprise a night vision (“NVIS”)sensor system; and the response curve can comprise one or more of: anNVIS response curve; an NVIS-A response curve; and an NVIS-B responsecurve.

The first images can comprise one or more of blue images, green imagesand red images, and the second images comprise infrared images, thecontroller can be further configured to determine the second visualsensor system intensity component of the first images using the responsecurve of the second visual sensor system by: multiplying, at thecontroller, the response curve by each spectral radiance curve of one ormore of: each light source of the first projector, and the first images;and summing, at the controller, results of each multiplication.

The first images can comprise one or more of blue images, green imagesand red images, and the second images comprise the red images, thecontroller can be further configured to determine the second visualsensor system intensity component of the first images using the responsecurve of the second visual sensor system by: multiplying, at thecontroller, the response curve by each spectral radiance curve of one ormore of: each light source of the first projector, and the first images;and summing, at the controller, results of each multiplication.

The controller can be further configured to reduce the intensity of thesecond images provided at the display device by the second visual sensorsystem intensity component by integrating the second visual sensorsystem intensity component to determine a total intensity thereof, andreducing the intensity of the second images by the total intensity,independent of wavelength.

The controller can be further configured to determine the second visualsensor system intensity component of the first images using the responsecurve of the second visual sensor system as a function of wavelength.

The controller can be further configured to reduce the intensity of thesecond images provided at the display device by the second visual sensorsystem intensity component of the first images, as a function ofwavelength.

Another aspect of the specification provides a method comprising: at asystem comprising: a display device configured to provide first images,viewable by a first visual sensor system, and second images, viewable bya second visual sensor system, the first images and the second imageshaving common features which align when the first images and the secondimages are provided concurrently, first images comprising wavelengthsviewable by the second visual sensor system; and, a controller,determining, at the controller, a second visual sensor system intensitycomponent of the first images using a response curve of the secondvisual sensor system; and, reducing, at the controller, intensity of thesecond images provided at the display device by the second visual sensorsystem intensity component of the first images, at least when the firstimages and the second images are concurrently provided.

The display device can comprise one or more projectors configured toprovide the first images and the second images concurrently by one ormore of: interlacing the first images and the second images; alternatingthe first images and the second images; and co-projecting the firstimages and the second images.

The first visual sensor system can comprise a human visual system andthe second visual sensor system can comprise a night vision sensor(“NVIS”) system.

The first visual sensor system can comprise a human visual system andthe second visual sensor system can comprise a night vision (“NVIS”)sensor system; and the response curve can comprise one or more of: anNVIS response curve; an NVIS-A response curve; and an NVIS-B responsecurve.

The first images can comprise one or more of blue images, green imagesand red images, and the second images comprise infrared images, and themethod can further comprise determining the second visual sensor systemintensity component of the first images using the response curve of thesecond visual sensor system by: multiplying, at the controller, theresponse curve by each spectral radiance curve of one or more of: eachlight source of the first projector, and the first images; and summing,at the controller, results of each multiplication.

The first images comprise one or more of blue images, green images andred images, and the second images comprise the red images, and themethod can further comprise determining the second visual sensor systemintensity component of the first images using the response curve of thesecond visual sensor system by: multiplying, at the controller, theresponse curve by each spectral radiance curve of one or more of: eachlight source of the first projector, and the first images; and summing,at the controller, results of each multiplication.

The method can further comprise reducing the intensity of the secondimages provided at the display device by the second visual sensor systemintensity component by integrating the second visual sensor systemintensity component to determine a total intensity thereof, and reducingthe intensity of the second images by the total intensity, independentof wavelength.

The method can further comprise determining the second visual sensorsystem intensity component of the first images using the response curveof the second visual sensor system as a function of wavelength.

The method can further comprise reducing the intensity of the secondimages provided at the display device by the second visual sensor systemintensity component of the first images, as a function of wavelength.

Another aspect of the specification provides a computer-readable mediumstoring a computer program, wherein execution of the computer program isfor: at a system comprising: a display device configured to providefirst images, viewable by a first visual sensor system, and secondimages, viewable by a second visual sensor system, the first images andthe second images having common features which align when the firstimages and the second images are provided concurrently, first imagescomprising wavelengths viewable by the second visual sensor system; and,a controller, determining, at the controller, a second visual sensorsystem intensity component of the first images using a response curve ofthe second visual sensor system; and, reducing, at the controller,intensity of the second images provided at the display device by thesecond visual sensor system intensity component of the first images, atleast when the first images and the second images are concurrentlyprovided. The computer-readable medium can comprise a non-transitorycomputer-readable medium.

BRIEF DESCRIPTIONS OF THE DRAWINGS

For a better understanding of the various implementations describedherein and to show more clearly how they may be carried into effect,reference will now be made, by way of example only, to the accompanyingdrawings in which:

FIG. 1 depicts a system for cross-talk reduction in visual sensorsystems, according to non-limiting implementations.

FIG. 2 depicts a block diagram of a flowchart of a method for cross-talkreduction, according to non-limiting implementations.

FIG. 3 depicts response curves of the visual sensor system of the systemof FIG. 1, as well as spectral radiance curves for each ofred-green-blue components of an image viewable by a human visual systemand a spectral radiance curve of infrared images viewable by nightvision goggles, according to non-limiting implementations.

FIG. 4 depicts a determination of an infrared contribution of each ofthe red-green-blue components of the image viewable by a human visualsystem depicted in FIG. 3, according to non-limiting implementations.

FIG. 5 depicts a determination a summing of the infrared contribution ofeach of the red-green-blue components of the image viewable by a humanvisual system depicted in FIG. 3, according to non-limitingimplementations.

FIG. 6 depicts a reduction of intensity of the infrared images byintegrating a night vision goggle response to the red-green-bluecomponents of an image viewable by a human visual system to determine atotal intensity thereof, and reducing the intensity of infrared imagesby the total intensity, independent of wavelength, according tonon-limiting implementations.

FIG. 7 depicts a reduction of intensity of the infrared images byintegrating a night vision goggle response to the red-green-bluecomponents of an image viewable by a human visual system to determine atotal intensity thereof, and reducing the intensity of infrared imagesby the total intensity as a function of wavelength, according tonon-limiting implementations.

FIG. 8 depicts an alternative system for cross-talk reduction in visualsensor systems, according to non-limiting implementations.

DETAILED DESCRIPTION

Attention is directed to FIG. 1 which depicts a system 100 for reducingcross-talk in visual sensor systems. System 100 comprises: a firstvisual sensor system 101, and a second visual sensor system 102,respective wavelength sensitivity ranges of first visual sensor system101 and second visual sensor system 102 can partially overlap; a displaydevice 103 configured to provide first images 111, viewable by firstvisual sensor system 101, and second images 112, viewable by secondvisual sensor system 102, first images 111 and second images 112 havingcommon features 113, 114 which align when first images 111 and secondimages 112 are provided concurrently, and first images 111 comprisingwavelengths viewable by second visual sensor system 102; a controller201; and a memory 120 storing: a response curve 122 of second visualsensor system 102. Controller 201 is generally configured to: determinea second visual sensor system intensity component of first images 111using response curve 122 of second visual sensor system 102; and, reduceintensity of second images 112 provided at display device 103 by thesecond visual sensor system intensity component of first images 112, atleast when first images 111 and second images 112 are concurrentlyprovided.

As depicted, memory 120 is a component of controller 201, which furthercomprises a communication interface 224.

Furthermore, as depicted, display device 103 comprises two projectors210-1, 210-2 (interchangeably referred to hereafter, collectively, asprojectors 210 and, generically, as a projector 210), and a screen 211onto which images 111, 112 are respectively projected by projectors210-1, 210-2.

Each projector 210 can comprise a digital projector configured todigitally project images 111, 112 using a respective light modulator.Projector 210 can include, but are not limited to, DLP™ (digital lightprocessing) DMD (digital multimirror device) based projectors, an LCOS(Liquid Crystal on Silicon) based projectors, and the like; however anytype of projector which can project images 111, 112 is within the scopeof present implementations. While not depicted, system 100 and/or eachprojector 210 can comprise other devices, including, but not limited to,warping devices and the like, configured to warp projection data forprojection by projectors 210 onto a surface. For example, each projector210 can comprise a respective controller configured to receiverespective images 111, 112 from controller 201, in the form of projectordata, and the like, and warp and/or adapt respective images 111, 112 forprojection onto screen 211. In particular, each projector 210 comprisesone or more respective light sources and/or illuminators configured toilluminate a respective light modulator.

Furthermore, while only two projectors 210 are depicted, system 100 cancomprise a plurality of projectors 210 and/or three or more projectors,each configured to project respective projection data comprising, forexample, portions of a larger tiled image to be projected.

Display device 103 can alternatively comprise one projector, adapted tointerlace images 111, 112, and/or alternate projecting of images 111,112.

Display device 103 can hence comprise one or more projectors 210configured to provide first images 111 and second images 112concurrently by one or more of: interlacing first images 111 and secondimages 112; alternating first images 111 and second images 112; andco-projecting (as depicted) first images 111 and second images 112.

System 100 can comprise a simulation environment and/or a visualizationenvironment, such a flight simulator used to train pilots under nightflying. As such, in these implementations, first images 111 compriseimages that are viewable by a human visual system, and can comprise, forexample a combination of red images, green images and blue images (“RGB”(red-green-blue”) images); and second images 111 can comprise the sameand/or similar images as first images 111, but viewable by night visiondevices, such as NVIS goggles and the like. Hence, in theseimplementations, projector 210-1 is generally configured to projectlight, including images 111, in a wavelength range visible to a humanvisual system such as about 400 nm to about 700 nm; and projector 210-2is generally configured to project infrared light, including images 112,in a wavelength range visible to an NVIS device, such as about 580 nm toabout 900 nm (NVIS-A), and/or about 620 nm to about 900 nm (NVIS-B).

In particular, for example, projector 210-1 can comprise an RGBprojector comprising a red light source, a green light source and bluelight source (e.g. three light sources and/or illuminators), all ofwhich are visible to a human visual sensor (“HVS”) system; further,projector 210-2 can comprise an infrared projector comprising aninfrared light source, visible to night vision devices. Each projector210 can be configured to control an intensity and/or a relativeintensity of each respective light source. In some implementations, eachprojector 210 can control a contribution of each respective light sourceto a respective image 111, 112 by increasing or reducing a totalintensity (e.g. by increasing or decreasing power to a respective lightsource, and/or by using modulation schemes, for example pulse widthmodulation and the like at a respective modulator). For example, inthese implementations, a particular shape of a spectral radiance curveof a color component of each respective image 111, 112 doesn't change,but merely a relative intensity. In other implementations, one or moreprojectors 210 can be configured to control a spectral radiance curve ofa color component of each respective image 111, 112 at least partiallyas a function of wavelength.

In any event, in these particular implementations, first visual sensorsystem 101 can comprise a human visual system and/or a human visualsensor (“HVS”) system, configured to view images in a range ofwavelengths viewable by a human being, which can include, but is notlimited to about 400 nm to about 700 nm. First visual sensor system 101can comprise one or more human eyes, however first visual sensor system101 can comprise one or more cameras, charge-coupled devices (CCDs), andeven camera film sensitive to light in a range of about 400 nm to about700 nm. In particular, first visual sensor system 101 can detect firstimages 111, when provided by display device 103, and visually conveyfirst images 111 to a user.

In particular implementations where first visual sensor system 101comprises an HVS system, second visual sensor system 102 can compriseone or more of a night vision (“NVIS”) sensor system, night vision(NVIS) goggles, an NVIS device, an NVIS heads-up display system, aninfrared detector and the like. In particular, first visual sensorsystem 101 detects light according to response curve 121 described inmore detail below. When second visual sensor system 102 comprise an NVISdevice and the like, the NVIS devices, and the like, can comprise NVIS-Agoggles and/or an NVIS-A device, and/or NVIS-B goggles and/or an NVIS-Bdevice, each detecting infrared light according to response curve 122(which, can comprise a plurality of response curves, for example anNVIS-A response curve and an NVIS-B response curve). When second visualsensor system 102 comprises an NVIS device, second visual sensor system102 can sense images 111, 112 independent of wavelength other thandetecting light according to response curve 121. In other words, imagesrendered by second visual sensor system 102 are generally monochromatic(e.g. black and white, black and green, black and yellow, and the like)as such NVIS devices can be configured to show where, in a field of viewof second visual sensor system 102 infrared light is present or notpresent, without reference to a wavelength of the infrared light.

Furthermore, while each of visual sensor systems 101, 102 are depictedas side-by-side in FIG. 1, in other implementations, second visualsensor system 102 can be used in conjunction with first visual sensorsystem 101, for example, when a user is wearing NVIS goggles.

Response curve 122 can be provisioned at memory 120 accordingly,depending on a type of NVIS devices, and the like, used with system 100.In general, NVIS devices are sensitive to infrared light; for examplefor NVIS-A devices detect infrared light in a range of about 580 nm toabout 900 nm, and NVIS-B devices detect infrared light in a range ofabout 620 to about 900 nm. Hence, in these implementations, secondvisual sensor system 102 can detect second images 112, when provided bydisplay device 103, and visually convey second images 112 to a user. Assuch, it is understood that respective wavelength sensitivity ranges offirst visual sensor system 101 and second visual sensor system 102 canat least partially overlap; hence, first images 111 produced for viewingby first visual sensor system 101 comprise wavelengths also viewable bysecond visual sensor system 102, as described below.

Hence, as depicted, first visual sensor system 101 can comprise a humanvisual sensor system and second visual sensor system 102 can comprise anight vision sensor (“NVIS”) system. Furthermore, when first visualsensor system 101 comprises a human visual system and second visualsensor system comprises a night vision (“NVIS”) sensor system, responsecurve 122 can comprises one or more of: an NVIS response curve; anNVIS-A response curve; and an NVIS-B response curve.

Furthermore, each of the NVIS-A, NVIS-B wavelength ranges (580 nm toabout 900 nm, and 620 nm to about 900 nm) overlap with the HVSwavelength range (400 nm to about 700 nm). Hence, when first images 111have a component in a range of about 580 nm to about 700 nm, such acomponent is viewable by second visual sensor system 102. Hence, firstimages 111 can contribute to the brightness of second images 112.

As depicted images 111, 112 each comprise a common feature 113, 114 of atree: while the depicted tree in each of images 111, 112 are offset,such an offset is merely shown for clarity, and it is appreciated thatthe depicted tree in each of images 111, 112 will be aligned, and/orprojected one-on-top-of-the-other such that each feature in the tree inimages 111 is generally aligned with each corresponding feature in thetree in images 112.

In other words, images 111, 112 generally have similar content, butimages 111 are provided in an HVS wavelength range such that images 111are visible to first visual sensor system 101, such as a human eye, andthe like, and images 112 are provided in an infrared wavelength rangesuch that images 112 are visible to second visual sensor system 102,such as NVIS goggles, and the like.

It is understood by persons of skill in the art that images 111, 112 donot need to be identical; for example, features that may be visible inan HVS wavelength range may not be visible in an infrared wavelengthrange, and hence such features can be included in first images 111 andomitted from second images 112 (and vice versa). However, commonfeatures (e.g. a tree canopy) that are visible in both an HVS wavelengthrange and an infrared wavelength range are aligned when projected ontoscreen 211, and positions of features that are particular to a givenwavelength range are nonetheless provided consistently in each of images111, 112 relative to the common features 113, 114. In other words, adesigner of images 111, 112 ensures that the user experience of system100 is consistent with operating an airplane at night (for example whensystem 100 comprises a flight simulator).

Hence, when a user is viewing screen 211 with the naked eye, images 111are visible, and when the user puts on NVIS goggles, the user sees thesame scene in infrared wavelengths by viewing images 112 through theNVIS goggles. Different features of the scene may be visible dependingon whether the user is wearing or not wearing the NVIS goggles, and suchdifferences can be encoded into images 111, 112.

Regardless, a portion of images 111 will also be visible through thegoggles as response curve 122 includes some visible wavelengths, whichcan provide an undesirable user experience. Indeed, when system 100includes a flight simulator, and the like, such overlap in wavelengthsensitivity ranges can even ultimately be dangerous as it provides apilot being trained to operate an airplane, and the like, using NVISgoggles with an incorrect understanding of the experience which couldlater lead to problems when operating airplanes, and the like, in nightflying conditions using NVIS goggles.

Hence, system 100 further comprises controller 201 which is adapted toaddress this issue, as described hereafter.

Controller 201 can include, but is not limited to, one or more of acontent player, an image generator, and image renderer, and the likewhich processes and/or “plays” and/or generates images 111, 112, forexample by producing projection data suitable for processing andprojection by each projector 210. Controller 201, can comprise anysuitable computing device, including but not limited to a graphicsprocessing unit (GPU), a graphics processing device, a graphicsprocessing engine, a video processing device, a personal computer (PC),a server, and generally memory 120 and a communication interface 224(interchangeably referred to hereafter as interface 224) and optionallyany suitable combination of input devices and display devices.

Controller 201 can hence comprise, for example, a server and the like,configured to generate and/or render images as image data, including,but not limited to images 111, 112. Alternatively, controller 201 cangenerate images 111, 112 using algorithms, and the like, for generatingimages. Indeed, it is appreciated that images 111, 112 can be stored atmemory 120 as data (as depicted) and/or generated in “real-time”,transmitted to each of projectors 210, in the form of projection data,which then uses the projection data to control a respective lightmodulator to modulate light to form and project respective images 111,112 onto screen 211.

Each of images 111, 112 can hence include, but is not limited to, one orAVI files, one or more JPG files, a PNG file, and the like. When images111, 112 are provided to each of projectors 210 in the form ofprojection data, the projection data can include, but is not limited to,HDMI data, VGA data, and/or video transport data. In other words,controller 201 can process images 111, 112 to produce respectiveprojection data which is transmitted to each projector 210 each ofwhich, in turn, processes the respective projection data into a formatsuitable for projection by a respective projector 210. However, a widevariety of architectures and image formats are within the scope ofpresent implementations.

Controller 201 comprise a processor and/or a plurality of processors,including but not limited to one or more central processors (CPUs)and/or one or more processing units and/or one or more graphicprocessing units (GPUs); either way, controller 201 comprises a hardwareelement and/or a hardware processor. Indeed, in some implementations,controller 201 can comprise an ASIC (application-specific integratedcircuit) and/or an FPGA (field-programmable gate array) specificallyconfigured to implement the functionality of controller 201. Hence,controller 201 is not necessarily a generic computing device and/or ageneric processor and/or a generic component, but a device specificallyconfigured to implement specific functionality, as described in furtherdetail below. For example, controller 201 can specifically comprise anengine configured for cross-talk reduction in visual sensor systems.

Memory 120 can comprise a non-volatile storage unit (e.g. ErasableElectronic Programmable Read Only Memory (“EEPROM”), Flash Memory) and avolatile storage unit (e.g. random access memory (“RAM”)). Programminginstructions that implement the functional teachings of controller 201as described herein are typically maintained, persistently, in memory120 and used by controller 201 which makes appropriate utilization ofvolatile storage during the execution of such programming instructions.Those skilled in the art recognize that memory 120 is an example ofcomputer readable media that can store programming instructionsexecutable on controller 201. Furthermore, memory 120 is also an exampleof a memory unit and/or memory module and/or a non-volatile memory.

In particular, memory 120 stores an application 236, which, whenprocessed by controller 201, enables controller 201 to: determine asecond visual sensor system intensity component of first images 111using response curve 122 of second visual sensor system 102; and, reduceintensity of second images 112 provided at display device 103 by thesecond visual sensor system intensity component of first images 111, atleast when first images 111 and second images 112 are concurrentlyprovided.

As depicted, memory 120 further stores an HVS response curve 121 offirst visual sensor system 101, which can be provisioned at memory 120accordingly, for example when an intensity of first images 111 is to bereduced by a first visual sensor system intensity component of secondimages 112; however, in general, provisioning of response curve 121 atmemory 120 is optional.

As depicted, memory 120 further stores spectral radiance curves 131 ofrespective light sources of each of projectors 210, as described in moredetail below.

Furthermore, specific functionality of components of system 100 can bemaintained at controller 201. For example, as described above,controller 201 can further play and/or generate image data to produceprojection data specific to a given projector 210, which is in turntransmitted to projectors 210, each of which projects respective images111, 112 based on the received projection data.

Interface 224 comprises any suitable wired or wireless communicationinterfaces which enable controller 201 to communicate with eachprojector 210 via a respective communication link, which can comprisewired and/or wireless communication links.

Attention is now directed to FIG. 3 which depicts a flowchart of amethod 300 for reducing cross-talk in visual sensor systems, accordingto non-limiting implementations. In order to assist in the explanationof method 300, it will be assumed that method 300 is performed usingsystem 100, and specifically by controller 201, for example whencontroller 201 processes application 236. Indeed, method 300 is one wayin which system 100 and/or controller 201 can be configured.Furthermore, the following discussion of method 300 will lead to afurther understanding of controller 201, and system 100 and its variouscomponents. However, it is to be understood that system 100and/controller 201 and/or method 300 can be varied, and need not workexactly as discussed herein in conjunction with each other, and thatsuch variations are within the scope of present implementations.

Regardless, it is to be emphasized, that method 300 need not beperformed in the exact sequence as shown, unless otherwise indicated;and likewise various blocks may be performed in parallel rather than insequence; hence the elements of method 300 are referred to herein as“blocks” rather than “steps”. It is also to be understood, however, thatmethod 300 can be implemented on variations of system 100 as well.

At block 301, controller 201 determine a second visual sensor systemintensity component of first images 111 using response curve 122 ofsecond visual sensor system 102.

At block 303, controller 201 reduces intensity of second images 112provided at display device 103 by the second visual sensor systemintensity component of first images 111, at least when first images 111and second images 112 are concurrently provided.

Method 300 will now be described with respect to FIG. 3 to FIG. 5.

Attention is next directed to FIG. 3 which depicts a non-limitingexample of response curve 121 of first visual sensor system 101 and aresponse curve 122 of second visual sensor system 102; as depicted,response curve 121 corresponding to a spectral sensitivity of a humaneye, and response curve 122 comprises an NVIS-B response curve. Asdescribed above, provisioning of response curve 121 at memory 120 can beoptional.

FIG. 3 further depicts a non-limiting example of a blue spectralradiance curve 311-B, a green spectral radiance curve 311-G and a redspectral radiance curve 311-R of at least one pixel of images 111, as afunction of wavelength, as well as a non-limiting example of a spectralradiance curve 312 of at least one pixel of images 112, as a function ofwavelength, each of which clearly includes an infrared component (e.g.wavelengths over about 700 nm). Spectral radiance curves 311-B, 311-G,311-R will be interchangeably referred to herein, collectively, asspectral radiance curves 311 and, generically, as a spectral radiancecurve 311. Furthermore, each of response curves 121, 122 and spectralradiance curves 311, 312 are provided in arbitrary units (AU).Furthermore, spectral radiance curves 311, 312 can be stored at memory120 as subsets of spectral radiance curves 131. In addition, it isappreciated that each of spectral radiance curves 311, 312 are providedas examples only, and furthermore spectral radiance curves 311 areprovided to illustrate that any of blue, green and red light sources ofprojector 210 can comprise an infrared component. In practise, however,blue, green and red light sources of RGB projectors can have spectralradiance curves that are centred on given blue, green and redwavelengths, with a smaller spread in wavelengths than depicted in eachspectral radiance curves 311. Similarly, spectral radiance curve 312represents an example spectral radiance curve of an infrared lightsource where non-infrared components (e.g. including HVS visualcomponents) are exaggerated.

In particular, response curve 122 represents a sensitivity of secondvisual system 102 as a function of wavelength. Similarly, spectralradiance curves 311, 312 each represent intensity as a function ofwavelength for corresponding pixels in each of images 111, 112. Forexample, spectral radiance curves 311-B, 311-G, 311-R can comprisespectral radiance curves of one or more blue, green and red pixels whichform part of common feature 113 in images 111, and spectral radiancecurve 312 can comprise a spectral radiance curve of an infrared pixelwhich forms the same part of common feature 114 in images 112 that iscorrespondingly formed by the one or more pixels represented by spectralradiance curves 311-B, 311-G, 311-R.

In other words, at any given time, pixels having spectral radiancecurves 311, 312 can be concurrently provided at screen 211, such pixelsbeing aligned and/or overlapping. Further, as each of spectral radiancecurves 311 clearly have a respective portion which overlaps withresponse curve 122, at least this overlapping portion is viewable bysecond visual sensor system 102.

For example, attention is next directed to FIG. 4 which depicts, in atop row, response curve 122 overlaid on each of spectral radiance curves311-B, 311-G, 311-R. An overlapping region can be determined bymultiplying response curve 122 by each of spectral radiance curves311-B, 311-G, 311-R. Hence, a bottom row of FIG. 4 depicts second visualsensor system intensity components 411-B, 411-G, 411-R of first images111. Specifically, each of intensity components 411-B, 411-G, 411-R aredetermined by multiplying response curve 122 by each spectral radiancecurve 311-B, 311-G, 311-R of first images 111 (e.g. at block 301 ofmethod 300).

Attention is next directed to FIG. 5 which depicts, at graph 501 a totalsecond visual sensor system intensity components 511 determined bysumming, as a function of wavelength, each of components 411-B, 411-G,411-R. In graph 502, total second visual sensor system intensitycomponent 511 is overlaid on spectral radiance curve 312 of images 112.Without correction, total second visual sensor system intensitycomponent 511 will be viewed by second visual sensor system 102concurrently with spectral radiance curve 312, which can mean thatcommon features provided in both images 111, 112 (e.g. common features113, 114) appear brighter than intended to second visual sensor system102. Hence, to correct this situation, controller 201 sums each ofcomponents 411-B, 411-G, 411-R to produce total second visual sensorsystem intensity component 511 and reduces intensity of second images112 by second visual sensor system intensity component 511 of firstimages 111. Various implementations for reducing intensity of secondimages 112 by second visual sensor system intensity component 511 offirst images 111 are within the scope of the present specification.

For example, attention is next directed to FIG. 6 which depictsimplementations in which intensity of second images 112 provided atdisplay device 103 is reduced by second visual sensor system intensitycomponent 511 by: integrating second visual sensor system intensitycomponent 511 to determine a total intensity thereof, and reducing theintensity of second images 112 by the total intensity, independent ofwavelength. For example, as depicted in graph 602, an area A1 of secondvisual sensor system intensity component 511 is determined byintegrating under the curve representing second visual sensor systemintensity component 511, such that area A1 represents the totalintensity of second visual sensor system intensity component 511. Then,as depicted in graph 603, a total intensity of spectral radiance curve312 is reduced by an intensity corresponding to area A1; hence, in graph603, spectral radiance curve 312 is reduced by a total intensity “A1” toa reduced spectral radiance curve 612. For example, as depicted in graph604, summing reduced spectral radiance curve 612 and second visualsensor system intensity component 511 will result in a total intensitycurve 693 having an area similar to that of spectral radiance curve 312and hence a similar brightness of images 112 results. For example, abrightness of common features 113 of images 111 will contribute to thebrightness of common features 114 of images 112 at second visual sensorsystem 102.

As depicted, a shape of such a total intensity curve 693 can have aspectral shape different from spectral radiance curve 312. However, assecond visual sensor system 102 may not be sensitive to wavelength,other than to received images 111, 112 according to response curve 121,the change in spectral shape of total intensity curve 693 (as comparedto spectral radiance curve 312) will not affect images 112.

Reduction of spectral radiance curve 312 to reduced spectral radiancecurve 612 can occur by one or more of reducing an intensity of aninfrared light source at projector 210-2, and using modulation schemesat projector 210-1 (including, but not limited to pulse width modulationand the like at a modulator thereof). Such a reduction in intensity isgenerally independent of wavelength in that reduced spectral radiancecurve 612 corresponds to a dimmed version of spectral radiance curve312, and each of curve 312, 612 generally have a similar shape.

Alternatively, intensity of second images 112 provided at display device103 can be reduced by second visual sensor system intensity component511 as a function of wavelength, for example in implementations whereprojector 210 is configured to control a shape of spectral radiancecurve 312 for second images 112. For example, with reference to graph703 in FIG. 7, second visual sensor system intensity component 511 canbe subtracted from spectral radiance curve 312, as a function ofwavelength, to produce adjusted spectral radiance curve 712. Hence,second images 112 are projected having adjusted spectral radiance curve712 such that when first images 111 having second visual sensor systemintensity component 511 are concurrently provided with second images 112having adjusted spectral radiance curve 712, the total brightness viewedby second visual sensor system 102 is a sum of visual sensor systemintensity component 511 and adjusted spectral radiance curve 712, whichproduces total intensity curve 793 similar to spectral radiance curve312 and hence total intensity curve 793 as viewed by second visualsensor system 102 results a brightness similar to the brightness ofspectral radiance curve 312. Again, brightness of common features 113 ofimages 111 will contribute to the brightness of common features 114 ofimages 112 at second visual sensor system 102.

Hence, in these implementations, controller 201 determines each of eachof components 411-B, 411-G, 411-R, as well as spectral radiance curve312, for example by processing images 111, 112 and response curve 122,and in turn produces projection data corresponding to images 112 havingan adjusted spectral radiance curve 712.

Furthermore, in either of the implementations described herein, firstimages 111 can comprise one or more of blue images, green images and redimages, and second images 112 can comprise infrared images, andcontroller 201 can be configured to determine second visual sensorsystem intensity component 511 of first images 111 using response curve122 of second visual sensor system 102 by: multiplying response curve122 by each spectral radiance curve 311 of each of first images 111(and/or of light sources of projector 210-1), and summing results ofeach multiplication, as function of wavelength. Furthermore, such adetermination can occur on a pixel-by-pixel basis. Put another way,controller 201 can be configured to determine second visual sensorsystem intensity component 511 of first images 111 using response curve122 of second visual sensor system 102 by multiplying response curve 122by each spectral radiance curve 311 of one or more of: each light sourceof the first projector 210-1, and first images 111; and summing resultsof each multiplication.

In other words, controller 201 can be further configured to determine asecond visual sensor system intensity component 511 of first images 111using response curve 122 of second visual sensor system 102 as afunction of wavelength, and on a pixel-by-pixel basis. In addition,controller 201 can be further configured to reduce the intensity ofsecond images 112 (provided at display device 103) by second visualsensor system intensity component 511 of first images 111, by a totalintensity, or as a function of wavelength, as well as on apixel-by-pixel basis.

Persons skilled in the art will appreciate that there are yet morealternative implementations and modifications possible. While method 300was described with respect to response curve 122 comprising an NVIS-Bresponse curve, response curve 122 can comprise an NVIS-A responsecurve, or any other NVIS response curve.

Furthermore, in some implementations, first images 111 can comprise oneor more of blue images, green images and red images, and second images112 can comprise respective red images rather than strictly infraredimages. For example, with reference to FIG. 3, first images 111 cancomprise blue images having response curve 311-B, green images havingresponse curve 311-G, and red images having response curve 311-R;however, second images 112 can comprise red images having response curve311-R, which can be the same or different as the red images from firstimages 111. In other words, in these implementations, system 100 reliessolely on infrared data encoded in red images to provide images detectedby the second visual sensor system 102.

Hence, rather than sum each of components 411-B, 411-G, 411-R to producetotal second visual sensor system intensity component 511, in theseimplementations controller 201 multiplying response curve 122 by eachspectral radiance curve 311-B, 311-G of each of the blue images and thegreen images, to produce components 411-B, 411-G, sums the results ofeach multiplication to produce a second visual sensor system intensitycomponent includes only blue and green components 411-B, 411-G, andreduces the intensity of the red images by the result, similar to thereduction of spectral radiance curve 312 to produce adjusted and/orreduced spectral radiance curves 612, 712, as described above.

Hence, in these implementations, first images 111 comprise one or moreof blue images, green images and red images, and second images 112comprise the red images, and controller 201 can be further configured todetermine the second visual sensor system intensity component of firstimages 111 using response curve 122 of second visual sensor system 102by: multiplying response curve 122 by each spectral radiance curve ofeach of the blue images and the green images, and summing results ofeach multiplication. The second visual sensor system intensity componentis then used to reduce the intensity of the red images.

Indeed, as the second visual sensor system intensity component by whichthe red images are reduced is generally in an infrared range, such areduction is generally not noticeable to first visual sensor system 101and/or if the reduction is noticeable, it is generally only in thefar-red and has little effect on the RGB appearance of first images 111.

There are yet more alternative implementations and modificationspossible. For example, while present implementations are described withrespect to projectors, display device 103 can comprise any displaydevice configured to provide images 111, 112 as described herein,including, but not limited to, one or more cathode ray tubes (“CRT”),one or more flat panel displays (such as liquid crystal displays,organic light emitting diode displays, plasma displays, and the like)configured to produce images viewable by both visual sensor systems 101,102. In some of these implementations, such displays provide RGB images,while in other implementations, such displays can be specificallyconfigured to provide infrared images and RGB images.

Furthermore, while present implementations have been described withrespect to RGB images and infrared images, and corresponding HVS andNVIS sensor systems, systems and methods provided herein can be adaptedfor any visual sensor systems having respective wavelength sensitivityranges that at least partially overlap. For example, in simulationenvironments, and the like, where a ultraviolet visual sensor system isused in place of an infrared sensor system, intensity of ultravioletimages can be reduced by ultraviolet components of RGB images.Similarly, in simulation environments, and the like, that include twovisual sensor systems imaging in two adjacent and at least partiallyoverlapping wavelength ranges (which does not necessarily include humanvisible wavelengths), intensity of images viewable by one visual sensorsystem can be reduced by a visual sensor system intensity component ofimages viewable by the other visual sensor system.

Indeed, such a reduction can occur for both visual sensor systems. Forexample, with reference to FIG. 3, a response curve 121 of first visualsensor system 101 can be used to determine a human visual component ofspectral radiance curve 312 of second images 112, and an intensity ofimages 111 could be reduced accordingly.

There are yet more alternative implementations and modificationspossible. For example, in system 100 spectral radiance curves 131 (e.g.spectral radiance curves 311, 312) are depicted as being stored atmemory 120. In some implementations, spectral radiance curves 131 can beprovisioned at memory 120 at a factory and/or in a provisioning process,in which spectral radiance curves 131 are provisioned at memory 120 byreceiving spectral radiance curves 131 from an external device usinginterface 224. However, in other implementations system 100 can beadapted to determine one or more of spectral radiance curves 131, andstore one or more spectral radiance curves 131 at memory 120.

For example, attention is next directed to FIG. 8, which depicts analternative depicts a system 100 a for reducing cross-talk in visualsensor systems. System 100 a is substantially similar to system 100 withlike elements having like numbers. However, in system 100, a displaydevice 103 a has been adapted to include projectors 210 a-1, 210 a-2which include respective sensors 810-1, 810-2. Otherwise, display device103 a and projectors 210 a-1, 210 a-2 are substantially similar,respectively, to display device 103 and projectors 210-1, 210-2.Projectors 210 a-1, 210 a-2 will interchangeably be referred tohereafter, collectively, as projectors 210 a and, generically, as aprojector 210 a. Similarly, sensors 810-1, 810-2 will interchangeably bereferred to hereafter, collectively, as sensors 810 and, generically, asa sensor 810.

Each sensor 810 is configured to sense spectral radiance curves 131 ofrespective illuminators of projectors 210 a. For example, sensor 810-1is configured to sense spectral radiance curves 311 of each light sourceof projector 210 a-1 (e.g. red, green and blue light sources).Similarly, sensor 810-2 is configured to sense spectral radiance curve31 s of the light source of projector 210 a-a (e.g. an infrared lightsource). Each sensor 810 hence generally comprises a photometer, aspectrophotometer, and the like, configured to sense light as a functionof wavelength and can be located anywhere in a respective projector 210a to sense light produced by respective light sources. Indeed, asdepicted in FIG. 8, each projector 210 a can use a respective sensor 810to sense respective spectral radiance curves of respective lightsources, and transmit the respective spectral radiance curves tocontroller 201 for storage at memory 120.

For example, as depicted, projector 210 a-1 transmits spectral radiancecurves 311 to controller 201, and projector 210 a-1 transmits spectralradiance curve 312 to controller 201, where controller 201 storesspectral radiance curves 311, 312 as spectral radiance curves 131 atmemory 120. Indeed, in FIG. 8 spectral radiance curves 131 at memory 120are depicted in broken lines as initially spectral radiance curves 131may be not stored at memory 120.

Indeed, FIG. 8 depicts a provisioning process in which spectral radiancecurves 131 (e.g. spectral radiance curves 311, 312) are provisioned atmemory 120; in some implementations, when system 100 a is turned on,and/or installed, controller 201 can request spectral radiance curves311, 312 from each of projectors 210 a, while, in other implementations,projectors 210 a can push and/or transmit spectral radiance curves 311,312 to controller 201 without a request. Either way, when controller 201receives spectral radiance curves 311, 312 from each of projectors 210a, controller 201 stores spectral radiance curves 311, 312 in spectralradiance curves 131 at memory 120. When spectral radiance curves 131 arenot initially stored at memory 120, controller 201 provisions spectralradiance curves 131 at memory 120 using spectral radiance curves 311,312. When spectral radiance curves 131 are initially stored at memory120 (e.g. in a previous provisioning process), controller 201 updatesspectral radiance curves 131 at memory 120 using spectral radiancecurves 311, 312 (for example replacing any previous spectral radiancecurves with spectral radiance curves 311, 312).

Indeed, one or more of the processes depicted in FIG. 8 can be repeatedperiodically, for example to update one or more spectral radiance curves131 at memory 120 in the event that one or more of spectral radiancecurves 311, 312 change over time. For example, controller 201 canperiodically request one or more spectral radiance curves 311, 312 fromprojectors 210 a and/or projectors 210 a can periodically transmitspectral radiance curves 311, 312 to controller 201. Alternatively, eachprojector 210 a can be configured to monitor respective light sourcesthereof using a respective sensor 810 and when change in one or morerespective light sources is detected (e.g. a change in absolute and/orrelative brightness, and/or a change in a distribution of wavelengths,and the like), a projector 210 a can transmit one or more spectralradiance curves 311, 312 to controller 201 either for the light sourceswhere a change is detected, and/or for all of the light sources.

As depicted, system 100 a further comprises an optional sensor 840,which can be similar to sensors 810, but located to sense light fromdisplay device 103 a (e.g. light reflected from screen 211). Sensor 840,when present, is in communication with controller 201. For example,sensor 840 can be adjacent to sensor systems 101, 102 and/orincorporated into one or more of sensor systems 101, 102. Hence, in analternative provisioning process and/or monitoring process, sensor 840can detect one or more spectral radiance curves 311, 312 and transmit tocontroller 201. In some implementations, each of projectors 210 a can becontrolled by controller 201 to initially, and/or periodically, projectonto screen 211 images using each respective light sources in asequence, such that sensor 840 can determine each of one or morespectral radiance curves 311-B, 311-G, 311-R, 312 in a sequence andtransmit one or more spectral radiance curves 311-B, 311-G, 311-R, 312to controller 201. Alternatively, controller 201 can determine whenimages 111, 112 of one color (e.g. using only one light source ofprojectors 210 a) are being projected on screen 211, and control sensor840 to acquire a corresponding spectral radiance curves 311-B, 311-G,311-R, 312.

Furthermore, in FIG. 8, sensor 810-1 can be optional, sensor 810-2 canbe optional and/or sensor 840 can be optional. For example, when sensor810-2 is present, but sensors 810-1, 840 are not present, system 100 ais configured to provision and/or monitor only light sources (e.g. aninfrared light source) of projector 210 a-2, and it is assumed thatspectral radiance curves of light sources of projector 210 a-1 areprovisioned at memory 120 for example at a factory and/or in aprovisioning process that does not include sensors 810-1, 840.Similarly, when sensor 810-1 is present, but sensors 810-2, 840 are notpresent, system 100 a is configured to provision and/or monitor onlylight sources (e.g. red, green and blue light sources) of projector 210a-1, and it is assumed that spectral radiance curves of light sources ofprojector 210 a-2 are provisioned at memory 120 for example at a factoryand/or in a provisioning process that does not include sensors 810-2,840.

In general, this disclosure is directed to a device and method forreducing cross-talk in visual sensor systems in which first imagesviewable by a first visual sensor system and second images viewable by asecond visual sensor system are concurrently provided at a displaydevice. The methods described herein can be advantageously applied tonight vision flight simulators to provide a more realistic trainingenvironment.

Those skilled in the art will appreciate that in some implementations,the functionality of controller 201 can be implemented usingpre-programmed hardware or firmware elements (e.g., application specificintegrated circuits (ASICs), electrically erasable programmableread-only memories (EEPROMs), etc.), or other related components. Inother implementations, the functionality of controller 201 can beachieved using a computing apparatus that has access to a code memory(not shown) which stores computer-readable program code for operation ofthe computing apparatus. The computer-readable program code could bestored on a computer readable storage medium which is fixed, tangibleand readable directly by these components, (e.g., removable diskette,CD-ROM, ROM, fixed disk, USB drive). Furthermore, it is appreciated thatthe computer-readable program can be stored as a computer programproduct comprising a computer usable medium. Further, a persistentstorage device can comprise the computer readable program code. It isyet further appreciated that the computer-readable program code and/orcomputer usable medium can comprise a non-transitory computer-readableprogram code and/or non-transitory computer usable medium.Alternatively, the computer-readable program code could be storedremotely but transmittable to these components via a modem or otherinterface device connected to a network (including, without limitation,the Internet) over a transmission medium. The transmission medium can beeither a non-mobile medium (e.g., optical and/or digital and/or analogcommunications lines) or a mobile medium (e.g., microwave, infrared,free-space optical or other transmission schemes) or a combinationthereof.

Persons skilled in the art will appreciate that there are yet morealternative implementations and modifications possible, and that theabove examples are only illustrations of one or more implementations.The scope, therefore, is only to be limited by the claims appendedhereto.

What is claimed is:
 1. A system comprising: a display device configuredto provide first images, viewable by a first visual sensor system, andsecond images, viewable by a second visual sensor system, the firstimages and the second images having common features which align when thefirst images and the second images are provided concurrently, firstimages comprising wavelengths viewable by the second visual sensorsystem; and, a controller configured to: determine a second visualsensor system intensity component of the first images using a responsecurve of the second visual sensor system; and, reduce intensity of thesecond images provided at the display device by the second visual sensorsystem intensity component of the first images, at least when the firstimages and the second images are concurrently provided.
 2. The system ofclaim 1, further comprising a memory storing: a response curve of thesecond visual sensor system and spectral radiance curves of one or moreof: light sources of the first projector; and the first images.
 3. Thesystem of claim 1, wherein the display device comprises one or moreprojectors configured to provide the first images and the second imagesconcurrently by one or more of: interlacing the first images and thesecond images; alternating the first images and the second images; andco-projecting the first images and the second images.
 4. The system ofclaim 1, wherein the first visual sensor system comprises a human visualsystem and the second visual sensor system comprises a night visionsensor (“NVIS”) system.
 5. The system of claim 1, wherein the firstvisual sensor system comprises a human visual system and the secondvisual sensor system comprises a night vision (“NVIS”) sensor system;and the response curve comprises one or more of: an NVIS response curve;an NVIS-A response curve; and an NVIS-B response curve.
 6. The system ofclaim 1, wherein the first images comprise one or more of blue images,green images and red images, and the second images comprise infraredimages, the controller further configured to determine the second visualsensor system intensity component of the first images using the responsecurve of the second visual sensor system by: multiplying the responsecurve by each spectral radiance curve of one or more of: each lightsource of the first projector; and the first images; and summing resultsof each multiplication.
 7. The system of claim 1, wherein the firstimages comprise one or more of blue images, green images and red images,and the second images comprise the red images, the controller furtherconfigured to determine the second visual sensor system intensitycomponent of the first images using the response curve of the secondvisual sensor system by: multiplying the response curve by each spectralradiance curve of one or more of: each light source of the firstprojector; and the first images; and summing results of eachmultiplication.
 8. The system of claim 1, wherein the controller isfurther configured to reduce the intensity of the second images providedat the display device by the second visual sensor system intensitycomponent by integrating the second visual sensor system intensitycomponent to determine a total intensity thereof, and reducing theintensity of the second images by the total intensity, independent ofwavelength.
 9. The system of claim 1, wherein the controller is furtherconfigured to determine the second visual sensor system intensitycomponent of the first images using the response curve of the secondvisual sensor system as a function of wavelength.
 10. The system ofclaim 1, wherein the controller is further configured to reduce theintensity of the second images provided at the display device by thesecond visual sensor system intensity component of the first images, asa function of wavelength.
 11. A method comprising: at a systemcomprising: a display device configured to provide first images,viewable by a first visual sensor system, and second images, viewable bya second visual sensor system, the first images and the second imageshaving common features which align when the first images and the secondimages are provided concurrently, first images comprising wavelengthsviewable by the second visual sensor system; and, a controller,determining, at the controller, a second visual sensor system intensitycomponent of the first images using a response curve of the secondvisual sensor system; and, reducing, at the controller, intensity of thesecond images provided at the display device by the second visual sensorsystem intensity component of the first images, at least when the firstimages and the second images are concurrently provided.
 12. The methodof claim 11, wherein the display device comprises one or more projectorsconfigured to provide the first images and the second imagesconcurrently by one or more of: interlacing the first images and thesecond images; alternating the first images and the second images; andco-projecting the first images and the second images.
 13. The method ofclaim 11, wherein the first visual sensor system comprises a humanvisual system and the second visual sensor system comprises a nightvision sensor (“NVIS”) system.
 14. The method of claim 11, wherein thefirst visual sensor system comprises a human visual system and thesecond visual sensor system comprises a night vision (“NVIS”) sensorsystem; and the response curve comprises one or more of: an NVISresponse curve; an NVIS-A response curve; and an NVIS-B response curve.15. The method of claim 11, wherein the first images comprise one ormore of blue images, green images and red images, and the second imagescomprise infrared images, and the method further comprises determiningthe second visual sensor system intensity component of the first imagesusing the response curve of the second visual sensor system by:multiplying, at the controller, the response curve by each spectralradiance curve of one or more of: each light source of the firstprojector, and the first images; and summing, at the controller, resultsof each multiplication.
 16. The method of claim 11, wherein the firstimages comprise one or more of blue images, green images and red images,and the second images comprise the red images, and the method furthercomprises determining the second visual sensor system intensitycomponent of the first images using the response curve of the secondvisual sensor system by: multiplying, at the controller, the responsecurve by each spectral radiance curve of one or more of: each lightsource of the first projector, and the first images; and summing, at thecontroller, results of each multiplication.
 17. The method of claim 11,further comprising reducing the intensity of the second images providedat the display device by the second visual sensor system intensitycomponent by integrating the second visual sensor system intensitycomponent to determine a total intensity thereof, and reducing theintensity of the second images by the total intensity, independent ofwavelength.
 18. The method of claim 11, further comprising determiningthe second visual sensor system intensity component of the first imagesusing the response curve of the second visual sensor system as afunction of wavelength.
 19. The method of claim 11, further comprisingreducing the intensity of the second images provided at the displaydevice by the second visual sensor system intensity component of thefirst images, as a function of wavelength.
 20. A non-transitorycomputer-readable medium storing a computer program, wherein executionof the computer program is for: at a system comprising: a display deviceconfigured to provide first images, viewable by a first visual sensorsystem, and second images, viewable by a second visual sensor system,the first images and the second images having common features whichalign when the first images and the second images are providedconcurrently, first images comprising wavelengths viewable by the secondvisual sensor system; and, a controller, determining, at the controller,a second visual sensor system intensity component of the first imagesusing a response curve of the second visual sensor system; and,reducing, at the controller, intensity of the second images provided atthe display device by the second visual sensor system intensitycomponent of the first images, at least when the first images and thesecond images are concurrently provided.